1. Field of the Invention
The present invention relates to a sheet presser and an image scanner or a facsimile machine, a copy machine, and a character recognizer, and others.
2. Discussion of Related Art
There is conventionally known a document reader for a copy machine or facsimile machine, for example, which has a contact image sensor (CIS) or line CCD scanner. In the document reader, the CIS or CCD scanner is disposed between a pair of feed rollers for feeding in each sheet of document on which is formed an image to be scanned, and a pair of paper ejection rollers, such that the CIS or CCD scanner is oriented in a direction perpendicular to the direction in which the sheet is fed or conveyed. A surface of the sheet conveyed is irradiated by a light and reflects the light and the reflected light is sensed by the CIS or CCD scanner.
To scan the image on the sheet with sharpness, a distance from a focus of an optical system of the CIS or CCD scanner to the surface of the sheet should be held constant, and therefore a sheet pressing member for pressing the sheet onto a scanning portion of the document reader is disposed at an appropriate position.
The sheet pressing member is disposed such that the pressing member is pivotable with respect to a main body of the machine and is biased by a spring member in a direction to be held in contact with a scanning surface of the document reader. Such a document reader is disclosed in JP-A-11-341220.